The Effects of Concurrent Strength and Endurance Training on Physical Fitness and Athletic Performance in Youth: A Systematic Review and Meta-Analysis

Greater improvement in aerobic capacity after a polarized training program including cycling interval training at low cadence (50-70 RPM) than freely chosen cadence (above 80 RPM)

This study compared the impact of two polarized training programs (POL) on aerobic capacity in well-trained (based on maximal oxygen uptake and training experience) female cyclists. Each 8-week POL program consisted of sprint interval training (SIT) consisting of 8-12 repetitions, each lasting 30 seconds at maximal intensity, high-intensity interval training (HIIT) consisting of 4-6 repetitions, each lasting 4 minutes at an intensity of 90-100% maximal aerobic power, and low-intensity endurance training (LIT) lasting 150-180 minutes with intensity at the first ventilatory threshold. Training sessions were organized into 4-day microcycles (1st day-SIT, 2nd day-HIIT, 3rd day-LIT, and 4th day-active rest), that were repeated throughout the experiment. In the first POL program, exercise repetitions during SIT and HIIT training were performed with freely chosen cadence above 80 RPM (POLFC group, n = 12), while in the second POL program with low cadence 50-70 RPM (POLLC group, n = 12). Immediately before and after the 8-week POL intervention, participants performed an incremental test to measure maximal aerobic power (Pmax), power achieved at the second ventilatory threshold (VT2), maximal oxygen uptake (VO2max), maximal pulmonary ventilation (VEmax), and gross efficiency (GE). Moreover, participants performed VO2max verification test. Analysis of variance showed a repeated measures effect for Pmax (F = 21.62; η2 = 0.5; p = 0.00), VO2max (F = 39.39; η2 = 0.64; p = 0.00) and VEmax (F = 5.99; η2 = 0.21; p = 0.02). A repeated measures x group mixed effect was demonstrated for Pmax (F = 4.99; η2 = 0.18; p = 0.03) and VO2max (F = 6.67; η2 = 0.23; p = 0.02). Post-hoc Scheffe analysis showed that increase in Pmax were statistically significant only in POLLC group. The Friedman test showed that VT2 differed between repeated measures only in the POLLC group (χ2 = 11; p = 0.001; W = 0.917). In conclusion, it was found that POL program where SIT and HIIT were performed at low cadence was more effective in improving aerobic capacity in well-trained female cyclists, than POL with SIT and HIIT performed at freely chosen cadence. This finding is a practical application for athletes and coaches in cycling, to consider not only the intensity and duration but also the cadence used during various interval training sessions.

Synergistic Effects of Concurrent Aerobic and Strength Training on Fitness in Children and Adolescents: A Multivariate and Network Meta-Analysis

The decline in fitness levels among children and adolescents underscores the urgent need for effective exercise interventions. Aerobic endurance training (ET) and resistance training (RT) are vital for physical development in this demographic. This study employs multivariate and network meta-analysis (NMA) to assess the impact of concurrent training (CT), which integrates both ET and RT, on youth physical fitness. The objective is to identify the distinct advantages of CT over either ET or RT alone, emphasizing demographic and training-specific variables. A systematic literature review of publications from 1980 onward was conducted through ISI Web of Science, PubMed/MEDLINE, and SPORTDiscus databases, adhering to the PICOS criteria for study selection. Data were analyzed using univariate, multivariate, and network meta-analyses in Stata 17.0, focusing on cardiorespiratory fitness and muscular strength. The methodological quality and risk of bias were evaluated using the PEDro scale and Egger's test, along with sensitivity analyses and meta-regression to explore heterogeneity and publication bias. This analysis included 36 studies with 2658 participants (mean age: 14.32 ± 2.29 years) from an initial 11 074 publications, indicating low bias risk (PEDro scores ≥ 6). Univariate meta-analysis showed no significant differences in maximal oxygen uptake (VO2max) between CT and ET (standardized mean difference [SMD] = 0.01; 95% confidence interval [CI]: -0.23 to 0.25; p = 0.93). In contrast, CT significantly improved countermovement jump (CMJ) compared to RT alone (SMD = 0.19; 95% CI: 0.01-0.36; p = 0.04). Multivariate analysis confirmed notable enhancements in endurance and explosiveness for CT compared to ET or RT. NMA indicated significant improvements in lower limb strength, CMJ, and VO2max across interventions compared to controls, with the consecutive resistance training followed by ET (CRE) group yielding the most significant CMJ improvement (SMD = 0.27; 95% CI: 0.07-0.47). Isolated RT showed the highest lower limb strength improvement (SUCRA score 80.1%), while CRE excelled in CMJ advancements (SUCRA score 93.4%), and the CRED group (alternating ET and RT) led in VO2max improvements (SUCRA score 81.6%). Furthermore, high-intensity interval training (HIIT) significantly enhanced VO2max compared to team sports. This meta-analysis emphasizes the effectiveness of CT in improving muscle power and VO2max in children and adolescents, surpassing isolated ET or RT, and advocates for integrating ET and RT to optimize physical performance. Future research should explore the mechanisms underlying these enhancements. Trial Registration: PROSPERO registration number CRD42022368452.

No beneficial effect of aerobic whole-body electromyostimulation on lower limbs strength and power - a randomized controlled trial

BACKGROUND

Applying whole-body electromyostimulation (wbEMS) to voluntary activation of the muscle is known to impact motor unit recruitment. Thus, wbEMS as an additional training stimulus enhances force-related capacities. This study aimed to evaluate the mono- and multiarticular strength adaptations to a running intervention with wbEMS compared to running without wbEMS.

METHODS

In a randomized controlled trial (RCT), 59 healthy participants (32 female/ 27 male, 41 ± 7 years) with minor running experience conducted an eight-week running intervention (2x/ week à 20 min) with a wbEMS suit (EG) or without wbEMS (control group, CG). Maximal isokinetic knee extensor and flexor strength and jump height during countermovement jumps were recorded prior and after the intervention to assess maximal strength and power.

RESULTS

Following eight weeks of running, maximal isokinetic knee extension torque decreased significantly over time for both interventions (EG Δ -4%, CG Δ -4%; F(1, 44.14) = 5.96, p = 0.02, η = 0.12). No changes were observed for flexion torque (F(1, 43.20) = 3.93, p = 0.05, η = 0.08) or jump height (F(1, 43.04) = 0.32, p = 0.57, η  = 0.01).

CONCLUSIONS

The outcomes indicate that there is no additional effect over neuromuscular function adaptations with the inclusion of wbEMS during running training. Knee extensor strength is even slightly reduced which supports the principle of training specificity in regards to strength adaptation. We conclude that strength improvements cannot be achieved by running with wbEMS.

TRIAL REGISTRATION

German Clinical Trials Register, ID DRKS00026827, date 10/26/21.

Sequencing Effects of Concurrent Strength and Endurance Training on Selected Measures of Physical Fitness in Young Male Soccer Players: A Randomized Matched-Pairs Trial

BACKGROUND

Various physical fitness qualities such as muscle strength, speed and endurance are related to soccer performance. Accordingly, the combination of strength and endurance training (i.e., concurrent training [CT]) is an often-encountered training regimen in soccer. Less is known about the effects of CT sequencing on performance in young soccer players. The aim of this study was to assess the sequencing effects of strength and intermittent endurance training applied within the same training session (intrasession) on measures of physical fitness and soccer performance in young soccer players.

METHODS

Fifty male adolescent soccer players volunteered to participate in this study which was conducted in the Netherlands in 2019. Players were randomly assigned to a strength-endurance (SE) or an endurance-strength (ES) group in matched pairs based on their countermovement jump (CMJ) performance at baseline. Both groups completed a 12-weeks in-season training program with two weekly CT sessions. Training sessions consisted of 15 min plyometric exercises and 15 min soccer-specific intermittent endurance training. Both groups performed the same training volumes and the only difference between the groups was the CT intrasession sequencing scheme (SE vs. ES). Pre and post intervention, proxies of muscle power (CMJ, squat jump [SJ]), linear sprint speed (30-m sprint test), agility (Illinois test with / without ball), and soccer performance (ball kicking velocity) were tested.

RESULTS

Data from 38 players aged 14.8 ± 1.0 years (body height 172.9 ± 8.1 cm, body mass: 57.0 ± 7.2 kg, soccer experience: 8.8 ± 2.8 years, age from peak-height-velocity [PHV]: +1.2 ± 1.0 years) were included. Significant main time effects were found for CMJ (p = 0.002, d = 0.55), SJ (p = 0.004, d = 0.51), the Illinois agility test with ball (p = 0.016, d = 0.51), and ball kicking velocity (p = 0.016, d = 0.51). Significant group-by-time interactions were observed for 30-m linear sprint speed (p < 0.001, d = 0.76) with ES showing greater improvements (p = 0.006, d = 0.85, Δ-5%).

CONCLUSIONS

Both CT-sequencing types improved performance in the tests administered. The intrasession CT sequencing (SE vs. ES) appears not to have a major impact on physical fitness adaptations, except for linear sprint speed which was in favor of ES.

A comparison of the effects of two protocols of concurrent resistance and aerobic training on physical fitness in middle school students

Objective

This study aimed to compare the effects of two concurrent training (CT) protocols on the physical fitness of middle school students.

Method

A 12-week quasi-experimental pre-test/post-test study was conducted with 157 middle school students (age = 12.48 ± 0.34, n = 90 females) divided into three groups: CT group A (CT-0h) received combined resistance training (RT) and aerobic training (AT) in each physical education session, CT group B (CT-48h) received RT and AT across two separate physical education classes 48 h apart, and a control group (Con) received no training. Training occurred twice a week. Test indicators included cardiorespiratory fitness (CRF) measured by estimated VO2max and 20 m shuttle run (laps), as well as muscle strength assessed through long jump, vertical jump, and handgrip strength.

Results

The intervention groups exhibited significant increases in estimated VO2max and muscle strength compared to their baseline values (p < 0.05). Both CT-0h and CT-48h groups demonstrated significant improvements in 20 m shuttle run (laps) (mean difference: 8.88 laps, p < 0.01; mean difference: 4.81 laps, p < 0.01, respectively), standing long jump (mean difference: 6.20 cm, p < 0.01; mean difference: 3.68 cm, p < 0.01, respectively), vertical jump (mean difference: 4.95 cm, p < 0.01; mean difference: 4.04 cm, p < 0.01, respectively), and handgrip strength (mean difference: 11.17 kg, p < 0.01; mean difference: 6.99 kg, p < 0.01, respectively). CT-0h group exhibited significantly increased estimated VO2max (mean difference: 1.47 ml/kg/min, p < 0.01) compared to the CT-48h group.

Conclusion

Both CT programs effectively improved adolescents' physical fitness indicators. However, the program that integrated RT and AT within the same physical education class demonstrated superior enhancement in adolescents' CRF.

Effects of acute moderate-intensity aerobic exercise on cognitive function in E-athletes: A randomized controlled trial

BACKGROUND

E-sports require athletes to have high-speed reflexes and excellent memory skills. Whereas a single session of aerobic exercise has been shown to improve cognitive function, this paper aims is to investigate the effects of acute moderate-intensity aerobic exercise on the cognitive function of e-sports players and its time-course characteristics.

METHODS

Thirty-four E-athletes were divided into 2 groups according to a random number table method, and 2 trials in a quiet physical fitness gym. The duration of each trial was approximately 1 hour. In the first trial: exercise group (64-76% of maximum heart rate for 30 minutes power cycling) and control group, cognitive function was tested, and results were automatically recorded before, immediately after, and 30 minutes after exercise using the human benchmark website (https://humanbenchmark.com). The second trial crossed and swapped the interventions of the 2 groups, and the other test protocols were the same as the first.

RESULTS

In both trials, the exercise intervention group showed significant improvements in speed accuracy (P < .001, Cohen's d = 1.406, 95% CI: 0.717-2.072; P = .005, Cohen's d = 0.782, 95% CI: 0.227-1.319), visual memory (P < .001, Cohen's d = 1.416, 95% CI: 0.725-2.086; P = .015, Cohen's d = 0.662, 95% CI: 0.127-1.181), and reaction time (P < .001, Cohen's d = 1.265, 95% CI: 0.610-1.898; P<.001, Cohen's d = 0.979, 95% CI: 0.386-1.551) immediately after exercise compared to baseline. The exercise intervention group also showed significant improvement in speed accuracy 30 minutes after exercise compared to baseline (P = .002 Cohen's d = 0.869, 95% CI: 0.298-1.421; P = .009, Cohen's d = 0.722, 95% CI: 0.177-1.249). In the first trial, the exercise intervention group showed significant improvements in visual memory and reaction time immediately after exercise compared to the control group (P = .013, Cohen's d = 0.904, 95% CI: 0.190-1.605; P = .027, Cohen's d = 0.796, 95% CI: 0.090-1.490). The exercise intervention group also showed significant improvement in reaction time 30 minutes after exercise compared to baseline (P = .009, Cohen's d = 0.719, 95% CI: 0.174-1.246). There was no effect of exercise on sequence memory or the chimp test in both trials (P > .05). Sequence effect analysis showed no influence on the order of the exercise intervention in both trials (P = .912; P = .111; P = .226).

CONCLUSION

Acute moderate-intensity aerobic exercise significantly enhanced the speed accuracy, visual reaction time, and instantaneous memory of eSports players, and the effect could be extended up to 30 minutes after exercise.

The effect of exercise training on serum concentrations of chemerin in patients with metabolic diseases: a systematic review and meta-analysis

CONTEXT

Elevated serum concentrations of chemerin is a significant factor in the development of metabolic disorders.

OBJECTIVE

This systematic review and meta-analysis evaluated the influence of exercise training on serum concentrations of chemerin in patients with metabolic diseases.

METHODS

Thirteen studies including 463 participants were included and analysed using a random-effects model to calculate weighted mean differences with 95% confidence intervals.

RESULTS

Results indicated that exercise training significantly decreased serum concentrations of chemerin in patients with metabolic diseases when compared with controls. Subgroup analysis showed that exercise training resulted in decreases in serum concentrations of chemerin in men, however, this was not significant in women. Moreover, subgroup analyses based on the type of exercise did not reveal differential effects on serum concentrations of chemerin.

CONCLUSION

Exercise training may produce improvements in serum concentrations of chemerin in patients with metabolic diseases. Further longer-term studies are needed to confirm these findings.

Effects of different exercise modalities and intensities on body composition in overweight and obese children and adolescents: a systematic review and network meta-analysis

Introduction: Childhood and adolescent overweight and obesity are global public health issues. Previous studies on exercise and overweight and obese children have produced inconsistent findings and lacked comparisons between different exercise modalities and intensities. Therefore, a network meta-analysis is necessary to provide evidence-based intervention programs. This study aims to identify the effects of different exercise modalities and intensities on changes in body composition in overweight and obese children and adolescents. Methods: A search for randomized controlled trials was conducted on Web of Science, PubMed, Scopus, and Embase involving exercise interventions aimed at improving body composition (body fat percentage, BMI, fat mass, fat-free mass, body weight) in overweight and obese children and adolescents. A random effects network meta-analysis was performed using STATA 14.0 software within a frequentist framework. The literature quality was assessed using the Cochrane Risk of Bias Tool 2.0. Results: Thirty-two papers involving 1,452 participants were included. There were six types of intervention involved in the study, including moderate intensity aerobic exercise, high-intensity aerobic exercise, moderate intensity resistance exercise, high-intensity resistance exercise, moderate intensity combined exercise, and high-intensity combined exercise. The network meta-analysis results revealed that high-intensity combined exercise was the best exercise mode for improving BMI [mean difference in kg/m² = -1.65, 95% CI (-3.27, -0.02)] and reducing fat mass [mean difference in kg = -2.87, 95% CI (-4.84, -0.91)]. Moderate intensity combined exercise was the best mode for weight loss [mean difference in kg = -4.58, 95% CI (-5.94, -3.22)] and improvement in body fat percentage [mean difference in% = -2.52, 95% CI (-3.83, -1.20)]. High-intensity resistance exercise had the optimal effect in increasing fat-free mass [mean difference in kg = 1.10, 95% CI (0.22, 1.99)]. Conclusion: In conclusion, the study found that combined exercise, whether moderate or high intensity, was more effective than any other exercise modality in improving body fat percentage and BMI, reducing fat mass and weight. Resistance exercise was the most effective in increasing fat-free mass.

Exercise Metabolome: Insights for Health and Performance

Exercise has many benefits for physical and mental well-being. Metabolomics research has allowed scientists to study the impact of exercise on the body by analyzing metabolites released by tissues such as skeletal muscle, bone, and the liver. Endurance training increases mitochondrial content and oxidative enzymes, while resistance training increases muscle fiber and glycolytic enzymes. Acute endurance exercise affects amino acid metabolism, fat metabolism, cellular energy metabolism, and cofactor and vitamin metabolism. Subacute endurance exercise alters amino acid metabolism, lipid metabolism, and nucleotide metabolism. Chronic endurance exercise improves lipid metabolism and changes amino acid metabolism. Acute resistance exercise changes several metabolic pathways, including anaerobic processes and muscular strength. Chronic resistance exercise affects metabolic pathways, resulting in skeletal muscle adaptations. Combined endurance-resistance exercise alters lipid metabolism, carbohydrate metabolism, and amino acid metabolism, increasing anaerobic metabolic capacity and fatigue resistance. Studying exercise-induced metabolites is a growing field, and further research can uncover the underlying metabolic mechanisms and help tailor exercise programs for optimal health and performance.

Effect of concurrent training on physical performance and quality of life in children with malignancy: A systematic review and meta-analysis

Objective

This study aims to evaluate the intervention effect of concurrent training on children with malignant tumors to provide evidence for prescribing exercise for children with malignant tumors.

Methods

Twelve databases were searched from inception to October 15, 2022. Two researchers independently screened the literature, evaluated the quality, extracted the data, and performed the meta-analysis using R.

Result

A total of nine randomized controlled trials involving 371 children were included in this study. The meta-analysis revealed that muscle strength was significantly greater in the exercise group compared to the usual care group [SMD = 0.26, 95% CI (0.04, 0.48), P = 0.023], with subgroup analysis showing no significant difference in upper limb [SMD = 0.13, 95% CI (−0.17, 0.43), P = 0.318] and a considerable difference in lower limb strength [SMD = 0.41, 95% CI (0.08, 0.74), P = 0.015]. Physical activity [SMD = 0.57, 95% CI (0.03, 1.1), P = 0.038], timed up and down stairs test [SMD = −1.22, 95% CI (−2.04, −0.4), P = 0.004], 6-min walking ability [SMD = 0.75, 95% CI (0.38, 1.11), P &lt; 0.01], quality of life [SMD = 0.28, 95% CI (0.02, 0.53), P = 0.033], and cancer-related fatigue [SMD = −0.53, 95% CI (−0.86, −0.19), P = 0.002] were significantly better than the usual care group. There were no significant differences in peak oxygen uptake [SMD = 0.13, 95% CI (−0.18, 0.44), P = 0.397], depression [SMD = 0.06, 95% CI (−0.38, 0.5), P = 0.791], and withdrawal rates [RR = 0.59, 95% CI (0.21, 1.63), P = 0.308] between the two groups.

Conclusion

Concurrent training could improve physical performance for children with malignancy but had no significant effect on mental health. Because the quality level of evidence is mostly very low, future high-quality randomized controlled trials are required to confirm these findings.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=364140, identifier CRD42022308176.

Physiological and Anthropometric Differences Among Endurance, Strength, and High-Intensity Functional Training Participants: A Cross-Sectional Study

Purpose: We compared aerobic capacity (V˙O2max), mitochondrial capacity (mV˙O2), anaerobic power, strength, and muscle endurance in healthy, active men from strength (STR), endurance (END) and high-intensity functional training (HIFT) backgrounds. Methods: Twenty-four men (n = 8/group) completed a cycle ergometer test to determine V˙O2max, followed by a 3-min all-out test to determine peak (PP) and end power (EP), and to estimate anaerobic [work done above EP (WEP)] and aerobic work capacity. Strength was determined by knee extensor maximal voluntary contraction at various flexion angles. The endurance index (EI) of the vastus lateralis (VL) was assessed by measuring muscle contraction acceleration during electrical twitch mechanomyography. mV˙O2max of the VL was assessed using near-infrared spectroscopy to estimate muscle oxygen consumption during transient femoral artery occlusions. Results: V˙O2max was significantly different among groups (p < .05). PP was significantly higher in HIFT and STR versus END (p < .05). EP was significantly higher in HIFT and END compared to STR (p < .05). WEP was significantly higher in STR compared to END (p < .05), whereas total work done was significantly higher in HIFT and END compared to STR (p < .05). mV˙O2max and EI were comparable between HIFT and END but significantly lower in STR versus END (p < .05). Torque production was significantly lower in END compared to STR and HIFT at all flexion angles (p < .05), with no difference between STR and HIFT. Conclusion: HIFT participants can exert similar power outputs and absolute strength compared to strength focused participants but exhibit fatigue resistance and mitochondrial capacity comparable to those who train for endurance.

Effects of Concurrent, Within-Session, Aerobic and Resistance Exercise Training on Functional Capacity and Muscle Performance in Elderly Male Patients with Chronic Heart Failure

BACKGROUND

The best format of exercise training (ET) in the setting of cardiac rehabilitation in patients with chronic heart failure (CHF) is still to be defined. Current guidelines recommend aerobic exercises, such as running and cycling, including some sessions per week of resistance exercise.

AIM

The aim of this study was to address the effectiveness of a concurrent exercise training program utilizing a circuit of sequential endurance and resistance exercises on functional capacity and muscular strength in patients with CHF.

METHODS

Ninety-five consecutive male patients (age 63.1 ± 6 years) with CHF (EF < 40%) in NYHA functional class II/III, were randomly assigned on 1:1 basis to a 12-week aerobic continuous training (AT) or concurrent CT), aerobic + resistance, training (CT), three times a week, with each session lasting 80 min. We used high quality, specifically designed ergometers, connected with each other and governed by a central console, and managed by a single physiotherapist. Before and after training all patients performed a symptoms-limited exercise test on a treadmill and a 6-min walking test (6MWT). Patients in the CT group also performed resistance exercises of upper and lower body.

RESULTS

The 6MWT and exercise duration at ergometric test increased significantly in both AT and CT groups, with the increase being greater in CT group (p < 0.001; ES = 0.13; p < 0.01; ES = 0.07). Muscular strength increased significantly in the CT group, particularly in the lower body muscular districts (p < 0.001). Quality of life improved in both groups, with a significantly greater improvement in the CT group (p < 0.05). No side effects leading to discontinuation of training were observed.

CONCLUSIONS

These findings indicate that concurrent, within-session training results in larger improvements in functional capacity, in addition to muscle performance, in patients with CHF, in comparison to single-mode aerobic training.

The Effectiveness of Physical Literacy Interventions: A Systematic Review with Meta-Analysis

BACKGROUND

The holistic concept of physical literacy assumes that individuals require adequate cognitive (knowledge and understanding), affective (motivation and confidence), and physical (physical competence) qualities to engage in lifelong physical activity behavior. In recent years, the research field has undergone rapid development and has also yielded an increasing number of interventions that aim to translate the theoretical-philosophical ideas into practical endeavors.

OBJECTIVE

The goal of the present pre-registered systematic review was to (a) provide a general overview of evaluation studies on physical literacy interventions and (b) to quantitatively examine the effectiveness of physical literacy interventions.

METHODS

Drawing on the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched a total of 18 databases for physical literacy interventions. Inclusion criteria were English language, publication by November 2021, and interventions using physical literacy as a theoretical underpinning or evaluation outcome. Articles that met these criteria were analyzed with respect to their basic delivery characteristics, study quality, evaluation approach, and main findings. We additionally ran meta-analyses with all non-randomized and randomized controlled trials to examine and compare the effect of these interventions on five outcome categories: (i) physical competence, (ii) motivation and confidence, (iii) knowledge and understanding, (iv) physical activity behavior, and (v) total physical literacy. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated to assess the effects on the different categories.

RESULTS

The screening process with two independent raters yielded 48 eligible interventions reported in 51 eligible articles. Quantitative evaluations most frequently addressed physical competence (72.2%), followed by motivation and confidence (47.2%), physical activity behavior (41.7%), and knowledge and understanding (33.3%). The controlled intervention studies (n = 24) exerted significant effects on all five physical literacy categories. Despite meaningful heterogeneity across the subgroups, the strongest effects were found for physical competence (SMD 0.90; 95% CI 0.55-1.25), followed by physical literacy aggregate scores (SMD 0.61; 95% CI 0.20-1.01), knowledge and understanding (SMD 0.54; 95% CI 0.30-0.79), physical activity behavior (SMD 0.39; 95% CI 0.23-0.55), and motivation and confidence (SMD 0.30; 95% CI 0.17-0.44).

CONCLUSIONS

The present study empirically demonstrated the effectiveness of physical literacy interventions on several outcomes relevant for promoting physical activity and health. To better inform current practices, future studies are advised to identify those program characteristics that significantly influence the effectiveness of physical literacy interventions.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42020188926.

Effects of Running-Specific Strength Training, Endurance Training, and Concurrent Training on Recreational Endurance Athletes' Performance and Selected Anthropometric Parameters

OBJECTIVE

The present study aimed to verify the effects of running-specific strength training alone, endurance training alone, and concurrent training on recreational endurance athletes' performance and selected anthropometric parameters.

METHOD

Thirty male recreational endurance runners were randomly assigned using a blocking technique to either a running-specific strength training group (RSSTG), an endurance training group (ETG), or a concurrent training group (CTG). RSSTG performed three strength-training sessions per week orientated to running, ETG underwent three endurance sessions per week, and CTG underwent a 3-day-per-week concurrent training program performed on non-consecutive days, alternating the strength and endurance training sessions applied to RSSTG and ETG. The training protocol lasted 12 weeks and was designed using the ATR (Accumulation, Transmutation, Realization) block periodization system. The following assessments were conducted before and after the training protocol: body mass (BM), body mass index (BMI), body fat percentage (BFP), lean mass (LM), countermovement jump (CMJ), 1RM (one-repetition maximum) squat, running economy at 12 and 14 km/h (RE12 and RE14), maximum oxygen consumption (VO₂max), and anaerobic threshold (AnT).

RESULTS

RSSTG significantly improved the results in CMJ, 1RM squat, RE12, and RE14. ETG significantly improved in RE12, RE14, VO₂max, and AnT. Finally, CTG, obtained significant improvements in BFP, LM, CMJ, 1RM squat, RE12, RE14, VO₂max, and AnT. RSSTG obtained improvements significantly higher than ETG in CMJ, 1RM squat, and RE14. ETG results were significantly better than those attained by RSSTG in AnT. Moreover, CTG marks were significantly higher than those obtained by ETG in CMJ and RE14.

CONCLUSION

Performing a 12-week concurrent training program integrated into the ATR periodization system effectively improves body composition and performance variables that can be obtained with exclusive running-specific strength and endurance training in recreational runners aged 30 to 40. Running-specific strength training enhances maximum and explosive strength and RE, whereas exclusive endurance training improves VO₂max, AnT, and RE. Performing concurrent training on non-consecutive days effectively prevents the strength and endurance adaptations attained with single-mode exercise from being attenuated. The ATR periodization system is useful in improving recreational endurance athletes' performance parameters, especially when performing concurrent training programs.

The association of aerobic, resistance, and combined exercises with the handgrip strength of middle-aged and elderly Korean adults: a nationwide cross-sectional study

Background

Handgrip strength (HGS), an indicator of overall muscle strength, is a key component in sarcopenia diagnosis. Although exercise is an effective strategy to prevent sarcopenia, the most appropriate exercise type targeting sarcopenia needs to be established. This study aimed to investigate the relationship between the physical activity (PA) patterns and HGS.

Methods

This was a cross-sectional study using the data from the 7th Korea National Health and Nutrition Examination Survey (2016–2018). The study population included 12,814 adults aged ≥ 40 years. According to the World Health Organization PA guidelines for public health, both aerobic (moderate to vigorous PA ≥ 150 min/week) and resistance exercises (≥ 2 sessions/week) are recommended. Study participants were categorized into one of the four groups depending on their adherence to each of two exercise guidelines (“neither,” “aerobic only,” “resistance only,” and “combined”). By defining normal HGS cutoff values as the lowest quartile of HGS from the population aged 20 years and above, we classified participants as “preserved” HGS group if their HGS was equal to or above the cutoff values. A Poisson regression model was used to calculate adjusted prevalence ratios (APRs) for preserved HGS across the four PA guideline adherences stratified by age and sex groups.

Results

In middle-aged adults, the “combined” exercise group was independently associated with the preserved HGS (male, age 50–59 years, APR = 1.072; male, age 60–69 years, APR = 1.180; female, age 50–59 years, APR = 1.112; female, age 60–69 years, APR = 1.188). For adults aged ≥ 70 years, meeting only aerobic or resistance exercise guidelines showed a positive association with HGS before adjusting for other health-related variables. In males of ≥ 70 years, the APR of preserved HGS was highest in the “combined” exercise group (“resistance only,” APR = 1.459, “combined,” APR = 1.664), while in women aged ≥ 70 years, the significance was lost after adjusting for covariates.

Conclusions

Adults meeting both aerobic and resistance exercise guidelines were associated with the highest prevalence of preserved HGS. Performing both types of exercise might be the most effective way to prevent sarcopenia that should be investigated in future clinical trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03293-z.

Effect of intra-session exercise sequence of an 8-week concurrent training program on the components of physical fitness in recreationally trained young adults

This study aimed to determine the effect of the intra-session exercise sequence of a concurrent training programme on the components of health-related physical fitness. Twenty-four healthy young adults were allocated into two different groups differing only in the exercise order to conduct an 8-week intra-session concurrent training programme consisting of three sessions of 60-90 minutes (180-270 min/week), with all-out running sprint intervals, back squat, and bench press endurance and resistance exercises (i.e., ET+RT and RT+ET). The 8-week intra-session concurrent training programme overall improved all the components of physical fitness regardless of the exercise sequence. However, ET + RT and RT + ET groups reported moderate and small improvements for squat jump (ET + RT: 3.82 cm [1.11 to 6.53 cm]; RT + ET: 0.31 cm [-1.72 to 2.33 cm]), countermovement jump (ET + RT: 3.76 cm [1.43 to 6.08 cm]; RT + ET: 2.07 cm [-0.03 to 4.17 cm]) and maximum oxygen uptake (ET + RT: 4.75 ml/kg/min [1.14 to 8.35 ml/kg/min]; RT + ET: 1.66 ml/kg/min [-0.89 to 4.21 ml/kg/min]), respectively. Therefore, greater lower-body power and cardiorespiratory fitness gains might be induced following the ET + RT sequence.

Effects of Resistance and Endurance Training Alone or Combined on Hormonal Adaptations and Cytokines in Healthy Children and Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

No previous systematic review has quantitatively compared the effects of resistance training, endurance training, or concurrent training on hormonal adaptations in children and adolescents. Objective was to examine the effects of exercise training and training type on hormonal adaptations in children and adolescents.

METHODS

A systematic literature search was conducted in the following databases: PubMed, Web of Science, and EBSCO. Eligibility criteria were: population: healthy youth population sample (mean age < 18 years); intervention: resistance training, endurance training, or concurrent training (> 4 weeks duration); comparison: control group; outcome: pre- and post-levels of hormones and cytokines; and study design: randomized and non-randomized controlled trials. We used a random-effect model for the meta-analysis. The raw mean difference in hormones from baseline to post-intervention was presented alongside 95% confidence intervals (CI). Further, the certainty of evidence quality and the risk of bias were assessed.

RESULTS

A total of 3689 records were identified, of which 14 studies were eligible for inclusion. Most studies examined adolescents with fewer studies on children (age < 12 years, N = 5 studies) and females (N = 2 studies). Nine exercise training programs used endurance training, five studies used resistance training, and no eligible study used concurrent training. The meta-analysis showed no significant effect of exercise training on testosterone (MD = 0.84 nmol/L), cortisol (MD = - 17.4 nmol/L), or SHBG (MD = - 5.58 nmol/L). Subgroup analysis showed that resistance training significantly increased testosterone levels after training (MD = 3.42 nmol/L) which was not observed after endurance training (MD = - 0.01 nmol/L). No other outcome differed between training types. Exercise training resulted in small and non-significant changes in GH (MD = 0.48 ng/mL, p = 0.06) and IGF-I (MD = - 22.90 ng/mL, p = 0.07). GH response to endurance training may be age-dependent and evident in adolescents (MD = 0.59 ng/mL, p = 0.04) but not when children and adolescents are pooled (MD = 0.48 ng/mL, p = 0.06). Limited evidence exists to conclude on IL-6 and TNF-α effects of exercise training. Assessments of GRADE domains (risk of bias, consistency, directness, or precision of the findings) revealed serious weaknesses with most of the included outcomes (hormones and cytokines).

CONCLUSIONS

This systematic review suggests that exercise training has small effects on hormonal concentrations in children and adolescents. Changes in testosterone concentrations with training are evident after resistance training but not endurance training. GH's response to training may be affected by maturation and evident in adolescents but not children. Further high-quality, robust training studies on the effect of resistance training, endurance training, and concurrent training are warranted to compare their training-specific effects.

REGISTRATION

PROSPERO: CRD42021241130.

Comparison of the Effect of Endurance, Strength, and Endurance-Strength Training on Inflammatory Markers and Adipokines Levels in Overweight and Obese Adults: Systematic Review and Meta-Analysis of Randomised Trials

The aim of this meta-analysis was to compare the effects of endurance, strength, and combined training on inflammatory markers and adipokine concentrations in overweight and obese adults. We performed a literature search of the Cochrane Library, PubMed, Scopus, and Web of Science databases and identified 24 randomised control trials published prior to June 2021. Our findings indicate that endurance training was significantly more beneficial than strength training in reducing C-reactive protein (CRP) (standard mean difference (SMD): -1.317, 95% confidence intervals (CI): -2.565, -0.070, p = 0.0385), interleukin 6 (IL-6) (SMD: -0.363, 95% CI: -0.648, -0.078, p = 0.0126), and visfatin (SMD: -0.618, 95% CI: -1.015, -0.222, p = 0.0023) concentrations. Moreover, combined training was more beneficial than strength training alone in lowering tumour necrosis factor-alpha (TNF-α) levels (SMD: 0.890, 95% CI: -0.301, 1.478, p = 0.0030). There were no differences between the effects of different types of training programmes on adiponectin and leptin concentrations. In conclusion, compared with strength training, endurance training is more effective in lowering CRP, IL-6, and visfatin concentrations, while combined training is more beneficial in reducing TNF-α levels in overweight and obese adults. Further studies are needed to determine which type of training has a better effect on adiponectin and leptin concentrations in this population.

Effects of Sand-Based Plyometric-Jump Training in Combination with Endurance Running on Outdoor or Treadmill Surface on Physical Fitness in Young Adult Males

This study aimed at examining the effects of nine weeks of sand-based plyometric-jump training (PJT) combined with endurance running on either outdoor or treadmill surface on measures of physical fitness. Male participants (age, 20.1 ± 1.7 years) were randomly assigned to a sand-based PJT combined with endurance running on outdoor surface (OT, n = 25) or treadmill surface (TT, n = 25). The endurance running intervention comprised a mixed training method, i.e., long slow distance, tempo, and interval running drills. A control group was additionally included in this study (CG, n = 25). Participants in CG followed their regular physical activity as OT and TT but did not receive any specific intervention. Individuals were assessed for their 50-m linear sprint time, standing long jump (SLJ) distance, cardiorespiratory fitness (i.e., Cooper test), forced vital capacity (FVC), calf girth, and resting heart rate (RHR). A three (groups: OT, TT, CG) by two (time: pre, post) ANOVA for repeated measures was used to analyze the exercise-specific effects. In case of significant group-by-time interactions, Bonferroni adjusted paired (within-group) and independent (between-group comparisons at post) t-tests were used for post-hoc analyses. Significant group-by-time interactions were found for all dependent variables (p < 0.001 - 0.002, ɳ_p ² = 0.16 - 0.78). Group-specific post-hoc tests showed improvements for all variables after OT (p < 0.001, Hedges'g effect size [g] = 0.05 - 1.94) and TT (p < 0.001, g = 0.04 - 2.73), but not in the CG (p = 0.058 - 1.000, g = 0.00 - 0.34). Compared to CG, OT showed larger SLJ (p = 0.001), cardiorespiratory fitness (p = 0.004), FVC (p = 0.008), and RHR (p < 0.001) improvements. TT showed larger improvements in SLJ (p = 0.036), cardiorespiratory fitness (p < 0.001), and RHR (p < 0.001) compared with CG. Compared to OT, TT showed larger improvements for SLJ (p = 0.018). In conclusion, sand-based PJT combined with either OT or TT similarly improved most measures of physical fitness, with greater SLJ improvement after TT. Coaches may use both concurrent exercise regimes based on preferences and logistical constrains (e.g., weather; access to treadmill equipment).

Concurrent Training Promotes Greater Gains on Body Composition and Components of Physical Fitness Than Single-Mode Training (Endurance or Resistance) in Youth With Obesity

The prevalence of obesity in the pediatric population has become a major public health issue. Indeed, the dramatic increase of this epidemic causes multiple and harmful consequences, Physical activity, particularly physical exercise, remains to be the cornerstone of interventions against childhood obesity. Given the conflicting findings with reference to the relevant literature addressing the effects of exercise on adiposity and physical fitness outcomes in obese children and adolescents, the effect of duration-matched concurrent training (CT) [50% resistance (RT) and 50% high-intensity-interval-training (HIIT)] on body composition and physical fitness in obese youth remains to be elucidated. Thus, the purpose of this study was to examine the effects of 9-weeks of CT compared to RT or HIIT alone, on body composition and selected physical fitness components in healthy sedentary obese youth. Out of 73 participants, only 37; [14 males and 23 females; age 13.4 ± 0.9 years; body-mass-index (BMI): 31.2 ± 4.8 kg·m-2] were eligible and randomized into three groups: HIIT (n = 12): 3-4 sets×12 runs at 80-110% peak velocity, with 10-s passive recovery between bouts; RT (n = 12): 6 exercises; 3-4 sets × 10 repetition maximum (RM) and CT (n = 13): 50% serial completion of RT and HIIT. CT promoted significant greater gains compared to HIIT and RT on body composition (p < 0.01, d = large), 6-min-walking test distance (6 MWT-distance) and on 6 MWT-VO2max (p < 0.03, d = large). In addition, CT showed substantially greater improvements than HIIT in the medicine ball throw test (20.2 vs. 13.6%, p < 0.04, d = large). On the other hand, RT exhibited significantly greater gains in relative hand grip strength (p < 0.03, d = large) and CMJ (p < 0.01, d = large) than HIIT and CT. CT promoted greater benefits for fat, body mass loss and cardiorespiratory fitness than HIIT or RT modalities. This study provides important information for practitioners and therapists on the application of effective exercise regimes with obese youth to induce significant and beneficial body composition changes. The applied CT program and the respective programming parameters in terms of exercise intensity and volume can be used by practitioners as an effective exercise treatment to fight the pandemic overweight and obesity in youth.

Effects of aerobic exercise combined with resistance training on health-related physical fitness in adolescents: A randomized controlled trial

Background

/Objective: This study aimed to compare the effects of two combined training methods on health-related physical fitness components in adolescents.

Methods

Seventy-six adolescents (16.1 ± 1.1 years, n = 44 female) were randomized into groups of moderate-intensity continuous training combined with resistance training (MICT + RT), high-intensity interval training combined with resistance training (HIIT + RT), or Control. The training sessions were performed twice weekly for 12 weeks. The health-related physical fitness components evaluated were: body composition, muscular and cardiorespiratory fitness.

Results

The intervention groups had a significant reduction in body fat percentage and improvement in abdominal repetitions and VO_2peak after 12 weeks of combined exercise program (p < 0.001). Intervention effects were found to significantly reduce body fat percentage for the MICT + RT and HIIT + RT groups compared to the control group (mean difference: −3.8; 95% CI: −6.2; −1 0.3; mean difference: −4.7; 95%CI: −7.1; −2.3, respectively). For muscle fitness, significant effects of the intervention were found in increasing the number of abdominal repetitions favoring the MICT + RT group compared to the control group (mean difference: 9.5; 95% CI: 4.4; 14.7) and HIIT + RT compared to the control group (mean difference: 14.1; 95% CI 9; 19.3). For cardiorespiratory fitness, significant effects of the intervention on improving VO_2peak were found in the experimental groups (MICT + RT vs Control group: mean difference: 4.4; 95% CI: 2.2; 6.6; and HIIT + RT vs. Control group: mean difference: 5.5, 95% CI: 3.3; 7.7).

Conclusion

The results suggest that 12 weeks of training using MCIT + RT or HIIT + RT showed a similar effect for health-related physical fitness components in adolescents.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

The Effects of Dietary Protein Supplementation on Acute Changes in Muscle Protein Synthesis and Longer-Term Changes in Muscle Mass, Strength, and Aerobic Capacity in Response to Concurrent Resistance and Endurance Exercise in Healthy Adults: A Systematic Review

BACKGROUND

Engaging in both resistance and endurance exercise within the same training program, termed 'concurrent exercise training,' is common practice in many athletic disciplines that require a combination of strength and endurance and is recommended by a number of organizations to improve muscular and cardiovascular health and reduce the risk of chronic metabolic disease. Dietary protein ingestion supports skeletal muscle remodeling after exercise by stimulating the synthesis of muscle proteins and can optimize resistance exercise-training mediated increases in skeletal muscle size and strength; however, the effects of protein supplementation on acute and longer-term adaptive responses to concurrent resistance and endurance exercise are unclear.

OBJECTIVES

The purpose of this systematic review is to evaluate the effects of dietary protein supplementation on acute changes in muscle protein synthesis and longer-term changes in muscle mass, strength, and aerobic capacity in responses to concurrent resistance and endurance exercise in healthy adults.

METHODS

A systematic search was conducted in five databases: Scopus, Embase, Medline, PubMed, and Web of Science. Acute and longer-term controlled trials involving concurrent exercise and protein supplementation in healthy adults (ages 18-65 years) were included in this systematic review. Main outcomes of interest were changes in skeletal muscle protein synthesis rates, muscle mass, muscle strength, and whole-body aerobic capacity (i.e., maximal/peak aerobic capacity [VO_2max/peak]). The quality of studies was assessed using the National Institute of Health Quality Assessment for Controlled Intervention Studies.

RESULTS

Four acute studies including 84 trained young males and ten longer-term studies including 167 trained and 391 untrained participants fulfilled the eligibility criteria. All included acute studies demonstrated that protein ingestion enhanced myofibrillar protein synthesis rates, but not mitochondrial protein synthesis rates during post-exercise recovery after an acute bout of concurrent exercise. Of the included longer-term training studies, five out of nine reported that protein supplementation enhanced concurrent training-mediated increases in muscle mass, while five out of nine studies reported that protein supplementation enhanced concurrent training-mediated increases in muscle strength and/or power. In terms of aerobic adaptations, all six included studies reported no effect of protein supplementation on concurrent training-mediated increases in VO_2max/peak.

CONCLUSION

Protein ingestion after an acute bout of concurrent exercise further increases myofibrillar, but not mitochondrial, protein synthesis rates during post-exercise recovery. There is some evidence that protein supplementation during longer-term training further enhances concurrent training-mediated increases in skeletal muscle mass and strength/power, but not whole-body aerobic capacity (i.e., VO_2max/peak).

Acute Effects of Aerobic Exercise on Muscle Strength and Power in Trained Male Individuals: A Systematic Review with Meta-analysis

BACKGROUND

Concurrent training can be an effective and time-efficient method to improve both muscle strength and aerobic capacity. A major challenge with concurrent training is how to adequately combine and sequence strength exercise and aerobic exercise to avoid interference effects. This is particularly relevant for athletes.

OBJECTIVE

We aimed to examine the acute effects of aerobic exercise on subsequent measures of muscle strength and power in trained male individuals.

DESIGN

We performed a systematic review with meta-analysis.

DATA SOURCES

Systematic literature searches in the electronic databases PubMed, Web of Science, and Google Scholar were conducted up to July 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included that applied a within-group repeated-measures design and examined the acute effects of aerobic exercise (i.e., running, cycling exercise) on subsequent measures of lower limb muscle strength (e.g., maximal isometric force of the knee extensors) and/or proxies of lower limb muscle power (e.g., countermovement jump height) in trained individuals.

RESULTS

Fifteen studies met the inclusion criteria. Aerobic exercise resulted in moderate declines in muscle strength (standardized mean difference [SMD] = 0.79; p = 0.003). Low-intensity aerobic exercise did not moderate effects on muscle strength (SMD = 0.65; p = 0.157) while moderate-to-high intensity aerobic exercise resulted in moderate declines in muscle strength (SMD = 0.65; p = 0.020). However, the difference between subgroups was not statistically significant (p = 0.979). Regarding aerobic exercise duration, large declines in muscle strength were found after > 30 min (SMD = 1.02; p = 0.049) while ≤ 30 min of aerobic exercise induced moderate declines in muscle strength (SMD = 0.59; p = 0.013). The subgroup difference was not statistically significant (p = 0.204). Cycling exercise resulted in significantly larger decrements in muscle strength (SMD = 0.79; p = 0.002) compared with running (SMD = 0.28; p = 0.035). The difference between subgroups was statistically significant (p < 0.0001). For muscle power, aerobic exercise did not result in any statistically significant changes (SMD = 0.04; p = 0.846).

CONCLUSIONS

Aerobic exercise induced moderate declines in measures of muscle strength with no statistically significant effects on proxies of muscle power in trained male individuals. It appears that higher compared with lower intensity as well as longer compared with shorter aerobic exercise duration exacerbate acute declines in muscle strength. Our results provide evidence for acute interference effects when aerobic exercies is performed before strength exercises. These findings may help practitioners to better prescribe single training sessions, particularly if environmental and/or infrastructural reasons (e.g., availability of training facilities) do not allow the application of strength training before aerobic exercise.

A combined training program's effect on anthropometry, body composition, physical fitness and blood pressure in elite police

BACKGROUND

Combined training (CT) simultaneously associates aerobic and strength exercises. Worldwide, studies on CT´s on Police officers' physical fitness are scarce. This study aims to measure a 4-month CT program's impact in the Close Protection Unit of the Portuguese Elite Police.

METHODS

A pre-and post-test study included 32 participants (mean age 30.1±2.7 years old). Anthropometry, body composition, physical fitness, and blood pressure assessments were collected. Statistical analysis was performed using IBM Statistical Package for Social Sciences (SPSS, 26.0) with a significance level at p≤0.05.

RESULTS

The main results showed an improvement in anthropometrics; aerobic capacity, strength, muscular endurance, and systolic blood pressure. However, a lean mass decrease, a fat mass increase, and worse results in other bioimpedance measures were observed.

CONCLUSIONS

In this study, the poor body composition results may imply a closer look for health concerns, although physical fitness has improved. Thus, it might be suggested that a CT program is helpful to increase physical fitness in elite police officers. Yet, improvements for its future application can be suggested, namely to include and address hydration level, nutrition, and rest/sleep moments. Moreover, because a high physical fitness level is needed in these population throughout their lifespan, ministerial policies should develop specific training programs, that can reduce morbidity and premature mortality, and have a major cos-teffectiveness impact on public health.

Strength Training Intensity and Volume Affect Performance of Young Kayakers/Canoeists

Purpose

The aim of this study was to compare the effects of moderate intensity, low volume (MILV) vs. low intensity, high volume (LIHV) strength training on sport-specific performance, measures of muscular fitness, and skeletal muscle mass in young kayakers and canoeists.

Methods

Semi-elite young kayakers and canoeists (N = 40, 13 ± 0.8 years, 11 girls) performed either MILV (70–80% 1-RM, 6–12 repetitions per set) or LIHV (30–40% 1-RM, 60–120 repetitions per set) strength training for one season. Linear mixed-effects models were used to compare effects of training condition on changes over time in 250 and 2,000 m time trials, handgrip strength, underhand shot throw, average bench pull power over 2 min, and skeletal muscle mass. Both between- and within-subject designs were used for analysis. An alpha of 0.05 was used to determine statistical significance.

Results

Between- and within-subject analyses showed that monthly changes were greater in LIHV vs. MILV for the 2,000 m time trial (between: 9.16 s, SE = 2.70, p < 0.01; within: 2,000 m: 13.90 s, SE = 5.02, p = 0.01) and bench pull average power (between: 0.021 W⋅kg^–1, SE = 0.008, p = 0.02; within: 0.010 W⋅kg^–1, SE = 0.009, p > 0.05). Training conditions did not affect other outcomes.

Conclusion

Young sprint kayakers and canoeists benefit from LIHV more than MILV strength training in terms of 2,000 m performance and muscular endurance (i.e., 2 min bench pull power).

The Effects of Exercise Serum From Prepubertal Girls and Women on In Vitro Myoblast and Osteoblast Proliferation and Differentiation

PURPOSE

In girls and women, the authors studied the effects of an acute bout of low-impact, moderate-intensity exercise serum on myoblast and osteoblast proliferation in vitro.

METHODS

A total of 12 pre/early pubertal girls (8-10 y old) and 12 women (20-30 y old) cycled at 60% VO2max for 1 hour followed by 1-hour recovery. Blood samples were collected at rest, mid-exercise, end of exercise, mid-recovery, and end of recovery. C2C12 myoblasts and MC3T3E1 osteoblasts were incubated with serum from each time point for 1 hour, then monitored for 24 hours (myoblasts) or 36 hours (osteoblasts) to examine proliferation. Cells were also monitored for 6 days (myoblasts) to examine myotube formation and 21 days (osteoblasts) to examine mineralization.

RESULTS

Exercise did not affect myoblast or osteoblast proliferation. Girls exhibited lower cell proliferation relative to women at end of exercise (osteoblasts, P = .041; myoblasts, P = .029) and mid-recovery (osteoblasts, P = .010). Mineralization was lower at end of recovery relative to rest (P = .014) in both girls and women. Myotube formation was not affected by exercise or group.

CONCLUSION

The systemic environment following one acute bout of low-impact moderate-intensity exercise in girls and women does not elicit osteoblast or myoblast activity in vitro. Differences in myoblast and osteoblast proliferation between girls and women may be influenced by maturation.

The pathophysiological effects of exercise in the management of idiopathic inflammatory myopathies: A scoping review

Idiopathic inflammatory myopathy (IIM) is a term used for a heterogeneous group of diseases characterized by severe muscle weakness. In addition to pharmacological treatment options, non-pharmacological methods such as exercising are essential for proper management of myositis. The present article aimed to provide an insight into the potential pathophysiological mechanisms underlying exercise-related benefits in myositis. A systematic search was performed on PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar using the following keywords and their combinations: "idiopathic inflammatory myopathy", "inflammatory myopathy", "myositis", "polymyositis", "dermatomyositis", "inclusion body myositis", and "exercise". Current literature indicates that exercising has impact on both immune and non-immune pathways in patients with IIM. Exercise-related benefits include (a) increased mitochondrial biogenesis/enzyme activity, (b) reconditioning of immune/inflammatory pathways, (c) decreased endoplasmic reticulum stress, (d) modulation of gene expression, (e) increased protein synthesis and cytoskeletal remodeling, and (f) decreased muscle fibrosis and non-muscle area infiltrates. With its certain benefits, exercise stands as a precious non-pharmacological treatment option for patients with IIM.

Effects of Velocity Loss Threshold Within Resistance Training During Concurrent Training on Endurance and Strength Performance

PURPOSE

This study analyzed the effects of 3 training interventions: 1 isolated endurance training (ET) and 2 concurrent training (CT), which differed in the velocity loss (VL) magnitude allowed during the resistance training (RT) set: 15% (VL15) versus 45%, on strength and endurance running performance.

METHODS

A total of 33 resistance- and endurance-trained men were randomly allocated into 3 groups: VL15, VL 45%, and ET. ET was similar across all groups. The CT groups differed in the VL allowed during the RT set. Before and after the 8-week training program the following tests were performed: (1) running sprints, (2) vertical jump, (3) progressive loading test in the squat exercise, and (4) incremental treadmill running test up to maximal oxygen uptake.

RESULTS

Significant differences (P < .001) in RT volume (approximately 401 vs 177 total repetitions for VL 45% and VL15, respectively) were observed. Significant "group" × "time" interactions were observed for vertical jump and all strength-related variables: the CT groups attained significantly greater gains than ET. Moreover, a significant "group" × "time" interaction (P = .03) was noted for velocity at maximal oxygen uptake. Although all groups showed increases in velocity at maximal oxygen uptake, the VL15 group achieved greater gains than the ET group.

CONCLUSIONS

CT interventions experienced greater strength gains than the ET group. Although all groups improved their endurance performance, the VL15 intervention resulted in greater gains than the ET approach. Therefore, moderate VL thresholds in RT performed during CT could be a good strategy for concurrently maximizing strength and endurance development.

Effects of Exercise Sequence and Velocity Loss Threshold During Resistance Training on Following Endurance and Strength Performance During Concurrent Training

PURPOSE

This study aimed to analyze the response to 4 concurrent training interventions differing in the training sequence and in the velocity loss (VL) threshold during strength training (20% vs 40%) on following endurance and strength performance.

METHODS

A randomized crossover research design was used. Sixteen trained men performed 4 training interventions consisting of endurance training (ET) followed by resistance training (RT), with 20% and 40% VL, respectively (ET + RT20 and ET + RT40), and RT with 20% and 40% VL, respectively, followed by ET (RT20 + ET and RT40 + ET). The ET consisted of running for 10 minutes at 90% of maximal aerobic velocity. The RT consisted of 3 squat sets with 60% of 1-repetition maximum. A 5-minute rest was given between exercises. The oxygen uptake throughout the ET and repetition velocity during RT were recorded. The blood lactate concentration, vertical jump, and squat velocity were measured at preexercise and after the endurance and strength exercises.

RESULTS

The RT40 + ET protocol showed an impaired running time along with higher ventilatory equivalents compared with those protocols that performed the ET without previous fatigue. No significant differences were observed in the repetitions per set performed for a given VL threshold, regardless of the exercise sequence. The protocols consisting of 40%VL induced greater reductions in jump height and squat velocity, along with elevated blood lactate concentration.

CONCLUSIONS

A high VL magnitude (40%VL) induced higher metabolic and mechanical stress, as well as greater residual fatigue, on the following ET performance.

CrossFit® Training Strategies from the Perspective of Concurrent Training: A Systematic Review

In the basic principles of CrossFit®, the goal is to improve fitness, related to the simultaneous development of strength and endurance. This is also the main idea of concurrent training, which has been researched since the 1980s. This article aimed to analyze the acute and chronic effects of CrossFit® and to assess the relevance of using the concurrent training methodology. The findings show that CrossFit® is an intense form of exercise that affects the function of the endocrine, immune, and central nervous systems. It also has potential in the development of strength and endurance parameters. These conclusions were compared with relevant concurrent training studies. Although the CrossFit® interventions (workouts of the day) have much in common with concurrent training, methodological recommendations can only be partially transferred. The approach for training and athlete development must be based on the originality of this sport.

Does A Multiple-Sport Intervention Based on the TGfU Pedagogical Model for Physical Education Increase Physical Fitness in Primary School Children?

Teaching Games for Understanding (TGfU) is one of the pedagogical models used for increasing health through physical education (PE), being associated with several psychological benefits. However, only few studies have studied the effect of TGfU on physical fitness. This study aims at assessing the changes in students' physical fitness after a six-month TGfU-based program with primary school children. A total of eight schools from the state of Sonora (Mexico) were randomly distributed into experimental (EG) and control group (CG). The final sample consisted of 188 pupils (100 boys, 88 girls; age = 10.22 ± 0.76 years) from the 5th and 6th grade. Employing a quasi-experimental design, physical fitness was assessed by means of the Eurofit test battery. At post-test, EG obtained significantly higher scores than CG in flexibility, abdominals, speed (p < 0.001), handgrip (p = 0.002), low-limb power (p = 0.032), and cardiorespiratory fitness (p = 0.048). Our findings suggest that TGfU can be a valid alternative to traditional methodologies not only when the aim of a PE unit is to stimulate the cognitive domain, but also for the development of physical fitness attributes that may help pupils develop in a comprehensive manner.

Resistance Training for Children and Adolescents

Resistance training is becoming more important as an integral part of comprehensive sport training regimens, school physical education classes, and after-school fitness programs. The increasing number of youth who are involved in sport activities, coupled with the health problems of inactivity and being overweight, have resulted in increased interest in resistance training. Secular declines in measures of muscular fitness in modern-day youth highlight the need for participation in youth resistance training for nonathletes as well as athletes. Parents often ask pediatricians to offer advice regarding the safety, benefits, and implementation of an effective resistance-training program. This report is a revision of the 2008 American Academy of Pediatrics policy statement and reviews current information and research on the benefits and risks of resistance training for children and adolescents.

CARDIOVASCULAR AND STRENGTH ADAPTATIONS IN CONCURRENT TRAINING IN HYPERTENSIVE WOMEN

ABSTRACT Introduction Physical exercise has been recommended as a non-pharmacological strategy for preventing and controlling hypertension. Objective To verify chronic cardiovascular and muscle strength adaptations in hypertensive women who underwent 12 weeks of concurrent training (CT) in different orders. Methods Twenty hypertensive women were randomly assigned into 2 groups: resistance exercise-endurance group (REE; 56.00 ± 5.20 years; 78.95 ± 8.28 kg; 155.10 ± 5.30 cm; 33.00 ± 5.30 kg.m-2) and endurance-resistance exercise group (ERE; 57.10 ± 13.38 years; 76.56 ± 18.87 kg; 155.50 ± 8.18 cm; 31.41 ± 5.84 kg.m-2). The endurance exercise was composed of 3 sets of 4 exercises, with 8-RM loads with a 90-second break between sets and exercises. The resistance exercise lasted for 25 minutes and was of progressive intensity. Muscle strength (8-RM), systolic and diastolic blood pressure, heart rate, and double product were assessed pre- and post-exercise. Results The ANOVA showed significant increases in strength for all exercises (p <0.0001) regardless of the order of the concurrent training (bench press, p = 0.680; leg press, p = 0.244; seated row, p = 0.668; and leg extension, p = 0.257). No significant differences in systolic (p = 0.074) and diastolic blood pressures (p = 0.064) were observed for different CT conditions. However, significant reductions in systolic (p = 0.0001) and diastolic blood pressures (p = 0.006) and double product (p = 0.006) only occurred in the REE group. Conclusion Endurance training and resistance exercise promote significant muscle strength gains after 12 weeks of training regardless of CT order in hypertensive women. Beneficial cardiovascular responses (SBP, DBP, and RPP) were also observed when endurance training was initiated. Level of evidence I; Therapeutic Studies - Investigating Treatment Outcomes.

The Way to Increase the Motor and Sport Competence Among Children: The Contextualized Sport Alphabetization Model

There is a concern to implement games that will be able to increase the students' motor and sport competence during the sport contents in Physical Education. Some games encompassed in Models-Based Practice (MsBP) are more beneficial for physical and physiological development than others. The main purpose of this study is to compare the degree of physical and physiological performance in several futsal games that have been implemented through two MsBP: the Teaching Games for Understanding (TGfU) and the Contextualized Sport Alphabetization Model (CSAM). The second objective is to analyze the relationship between physical and physiological variables. A quasi-experimental and cross-sectional study with pre- and post-test evaluations had been carried out. The sample was composed of 112 Primary Education students from First to Sixth grade (9.35 ± 1.76 years). Polar Team Pro® technology was implemented to compare and analyze the physical and physiological variables. Data was analyze comparing both models with a two-step cluster model. Afterward, Student's t-test was executed to compare the progression of both models. Besides, two-level multilevel model (MANOVA-ANOVA, followed by MANCOVA- ANCOVA) were also executed by means of applying a 4 versus 4 Small-Sided and Conditioned Game (SSCG). Finally, Pearson correlation between physical and physiological variables was calculated. Results showed that physical and physiological performance was higher in CSAM groups. In this regard, throughout the intervention of both models, results showed significant differences in physical and physiological variables at SSCGs implemented in the CSAM over the games implemented during the TGfU. Additionally, multilevel and MANCOVA post-test analyses shows significant differences in the physical and physiological performance during the post-test 4 vs. 4 SSCG at the CSAM students, in contrast to the TGfU students (p < 0.001). These results demonstrate that both physical (e.g., distance covered) and physiological performance (e.g., Edwards' TRIMP) are significantly higher during CSAM in contrast to TGfU. Moreover, relationship between physical and physiological variables help teachers to adapt sessions to the features of the context.

Expert's Choice: 2018's Most Exciting Research in the Field of Pediatric Exercise Science

This commentary highlights 23 noteworthy publications from 2018, selected by leading scientists in pediatric exercise science. These publications have been deemed as significant or exciting in the field as they (a) reveal a new mechanism, (b) highlight a new measurement tool, (c) discuss a new concept or interpretation/application of an existing concept, or (d) describe a new therapeutic approach or clinical tool in youth. In some cases, findings in adults are highlighted, as they may have important implications in youth. The selected publications span the field of pediatric exercise science, specifically focusing on: aerobic exercise and training; neuromuscular physiology, exercise, and training; endocrinology and exercise; resistance training; physical activity and bone strength; growth, maturation, and exercise; physical activity and cognition; childhood obesity, physical activity, and exercise; pulmonary physiology or diseases, exercise, and training; immunology and exercise; cardiovascular physiology and disease; and physical activity, inactivity, and health.

A Brief Review on Concurrent Training: From Laboratory to the Field

The majority of sports rely on concurrent training (CT; e.g., the simultaneous training of strength and endurance). However, a phenomenon called “Concurrent training effect” (CTE), which is a compromise in adaptation resulting from concurrent training, appears to be mostly affected by the interference of the molecular pathways of the underlying adaptations from each type of training segments. Until now, it seems that the volume, intensity, type, frequency of endurance training, as well as the training history and background strongly affect the CTE. High volume, moderate, continuous and frequent endurance training, are thought to negatively affect the resistance training-induced adaptations, probably by inhibition of the Protein kinase B—mammalian target of rapamycin pathway activation, of the adenosine monophosphate-activated protein kinase (AMPK). In contrast, it seems that short bouts of high-intensity interval training (HIIT) or sprint interval training (SIT) minimize the negative effects of concurrent training. This is particularly the case when HIIT and SIT incorporated in cycling have even lower or even no negative effects, while they provide at least the same metabolic adaptations, probably through the peroxisome proliferator-activated receptor-γ coactivator (PGC-1a) pathway. However, significant questions about the molecular events underlying the CTE remain unanswered.